This invention pertains to aseptic systems and their use for transferring fluid into, or out of, an enclosure such as a tank, a pipe, or other type of enclosure vessel, or between enclosure vessels. The invention pertains, for example, to transferring fluids into process systems which are sensitive to contamination from the outside environment.
Particularly this invention pertains to transferring higher viscosity fluids, such as bacteria cultures, starter materials, mother cultures, additives and the like, into processes where the combination in the enclosure is further processed in an aseptic environment. In such processes, contamination of either the fluid transferred, or the other process material into which the fluid is transferred, is unacceptable. Similarly, the invention pertains to transferring such fluids between tanks, and other enclosures, such as components of one or more processing systems.
The word "enclosure" as used herein refers to any closed containment structure without respect to its size. Thus it includes such small enclosures as cans which may be used in shipping starter bacteria from a culture lab. On the other end of the size spectrum, it includes large tanks, which may have capacities of several thousand gallons, or more, such as are used in the dairy processing industry.
Hereinafter, the invention is described with respect to its application to the processing of dairy products. It is contemplated that both the apparatus of the invention and the methods of the invention have application to a wide variety of particularly industrial processes which require the transferring of fluid components without introducing contaminating material into a processing enclosure. While the description concentrates on the use of the invention in the dairy industry, it is appreciated that similar applications can be made in other industries in light of the description of the invention herein.
In the processing of dairy products, and particularly that processing which uses bacterial cultures, the processor typically obtains a container of culture media from a culture supplier. The culture media is introduced into a "mother culture tank" where it is multiplied significantly in volume, and then distributed to the next processing stage in the dairy processing plant for the various processing operations. It is conventional practice to receive the culture media from the supplier in a metal can or similar container. In introducing the culture into the mother culture tank, the can is opened and the contents poured into the tank through an open port. This process of opening the can exposes the contents of the can to the outside environment. Opening the port on the mother culture tank exposes the inside of the mother culture tank, and culture media in the mother culture tank, to the outside environment. The combination of exposing both the mother tank and its culture media, and the contents of the culture can, to the outside environment and its inherent supply of contaminants, carries substantial risk of introducing airborne organisms such as bacteriophage or the like into the process. This is particularly critical since the general process of the operation is designed to encourage growth of "desirable strains of" bacteria.
Some processors have addressed the problem of contamination at the step of introducing the culture media to the mother tank by attempting to keep sterile the room in which the mother tank is housed. As is well known, sterile conditions are fairly successfully achieved for smaller spaces and volumes. But as the size of the space being sterilized increases, the cost of sterilizing practices increases significantly and the accompanying effectiveness of sterilizing practices decreases. Thus sterile room practices are not entirely satisfactory as (i) they are generally too costly, and (ii) adequate sterility may not be achieved.
Other processors have addressed the contamination problem in other ways, as by attempting to further control the amount of bacteria immediately adjacent the open port. In one method of controlling the bacteria around the open port, a ring of fire is generated around the open port by, for example, a natural gas burner device, whereby it is contemplated that bacteria in the vicinity of the open port are destroyed by the heat of the fire. The fire may also have a destructive effect on bacteria which may become attached to the culture as the culture is being poured through the port. However, the same heat which may be destructive to undesired bacteria in the environment as it is passing through the ring of fire may also be destructive to some part of the desired culture bacteria as it is being passed through the fire ring while being introduced into the tank through the open port. At least one supplier suggests that the culture can contents should be still partly frozen when added to the prepared culture medium in the tank.
As alternatives to the use of a fire ring, some processors have been known to use a steam ring in place of the fire ring. In addition some use of chlorination procedures around the opening is also known.
Another problem in the dairy processing industry is that the valves and pumps typically used to transfer, for example, the processed material from the mother culture tank to the processing tanks are difficult to keep clean and sanitized. And so special techniques, such as steam tracing and steam jacketing of pumps and valves, have been developed to assure the maintenance of aseptic conditions. But these are time consuming and expensive procedures, requiring a high level of training and skill on the part of the operator, as well as the operators' alert attention. Along with such complex procedures goes the risk of human error, whereby contaminated product might be produced and shipped--to the processor's detriment and liability. So the process is not only complex and costly, it also carries a risk of failure by virtue of its complexity. Further, such techniques carry environmental costs to air condition plants containing such steam processes. Plus, workmen can easily be burned by the hot equipment.
Thus it would be desirable to have a method of transferring material into and out of an enclosure which is sensitive to contamination from the outside environment, and to make those transfers in an assuredly aseptic manner. And it would be desirable to have apparatus appropriate for facilitating such transfers.
It is an object of this invention to provide apparatus for transferring a composition into or out of an enclosure while assuring the maintenance of the aseptic condition in the enclosure and preventing the introduction of contaminants into the enclosure, or into the process material, in the process of making the transfer.
It is another object to provide a method of making such an aseptic transfer.
It is yet a further object to provide necessary fittings and associated components to affect the fluid transfer through a fluid receiver assembly and a needle bundle assembly.
It is yet another object to provide a needle holder for holding needles in a needle bundle assembly. The needle bundle assembly facilitates the smooth functioning of the process of inserting the needles through the fluid receiver assembly into the interior of the enclosure.
It is still another objective to provide novel apparatus and means for transferring material from one stationary tank to another tank, without exposing the interior of either tank, or the material being transferred, to the outside environment.